PLANO — Look at Plano's skyline today, and you'll see more and more cranes. There is so much work already happening at the Legacy West and Toyota headquarters projects.

But there is one issue about the city's growth that has seen its share of hurdles: A plan named Plano Tomorrow.

"This is an issue that should be debated by the entire city, and not left to a few Council members," said Jack Ternan with Brewer, Attorneys and Counselors.

Plano Tomorrow was adopted by the city late last year. In a nutshell, it is a redevelopment of existing Plano and a plan for what to do with the seven percent of its footprint that remains untouched.

The plan was met with opposition from some groups like Plano Future that are worried about the kind of growth being proposed. The groups told WFAA last year they are worried about more apartments and more traffic.

Nearly 4,000 people signed a petition calling for a referendum on the plan, but it was denied by the city last year.

"The city charter clearly calls for a process when the public submits a petition," Ternan said. "That process clearly has not been followed."

The group fighting the plan hired lawyers with Brewer, Attorneys and Counselors. They are hoping to fight the procedural issues, they say, that are keeping the people from voting on the plan.

"The City of Plano has received a letter from an attorney regarding the November 2015 petition on the Plano Tomorrow Comprehensive Plan," said city spokesman Steve Stoler.

The city can't say much more, especially because of the threat of a lawsuit. The city had a deadline to respond to these attorneys and the group by Monday. That deadline was extended to Tuesday.